Rock-drilling device



(No Mdel.)l

T. MURDOGK.

ROCK DRILLING DEVIGE.

Patented Feb. 15, 1887.

UNITED Srarns Parnn'r OFFICE.

THOMAS MURDOOK, OF MIDDLETOVN, OONNEOTICUT, ASSGNOR TO THE KNOX ROCK BLASTING COMPANY, OF PITTSBURG, PENNSYLVANIA.

ROCK=DRlLLlNG DEVICE.

SPECIFICA'I'ION forming part of Letters Patent No. 357,729, dated February 15, 1887.

(No model.)

To ctZl whom it may concern:

Be it known that I, THoMAs MURDooK, of Middletown, in the county of Middlesex and State of Conneeticut, have invented a certain new and useful Improvement in RockDrilling Devices, of which the following is a description, reference being had to the accompanying drawings, where- Figure 1 is a plan of the guideplate with the drill cut in horizontal section. Fig. 2 is a side View of the device in plac-e for use, with the rock cut in vertical section through the center of the previously-drilled round hole. Fig. 3 is a view from above on the horizontal section denoted by dotted line x x. Fig. 4 is an enlarged side view of the lower end of the drill. Fig. 5 is an enlarged edge view of the lower end of the drill. Fig. 6 is an enlarged end view of the lower end of the drill.

Previous to the making of this improvement it was known that the alignment of a fracture of rock caused by exploding a blast in a hole drilled in the rock might be Controlled by first' drilling a round hole and then making two similar V-shaped grooves in opposite sides of the hole.

My improvement consists in a device 'for more effectually putting this idea in practice, the special obj ect being to accurately guide a tool which makes the side V-sha-ped grooves ln 1the wall of the previouslydrilled round The letter a denotes the body of the drill, which is square, (or the equivalent polygonal shape.) At its lower end this square-bodied drill is furnished with lateral Cutting-wings a', which cut the V shaped grooves in the previously-drilled round hole. The square shape of the drill has among others two features of use in operation, to Wit: First, it can operate with a correspondingly-shaped mortise in the guide-plate, soon to be described, so that it shall not turn rotarily while being driven vertically,and, second, the space between the sides of the drill and the wall of the round hole gives room for dbris.

The letter b denotes the guide-plate, made of iron, with a square inortise in one edge thereof, corresponding to the square shape of the body of the drill. It is made in the edge of the guideplate, for the reason that the drill cannot be introduced into the mortise endwise, by reason of the prcsence of the lateral Cutting-wings at the lower end of the drill, and by reason of a battering of the upper end of the drill, which necessarily takes place in hammering thereupon to drive downward in the hole.

The letters c denote screw-pins penetrating the guide-plate, screwing therein, provided at the upper ends with proper thunib-plates, and somewhat bluntly pointed at the lower ends to enter corresponding pinholes to be ihade in the face of the rock. These screwpins enter such pin-holes in the face of the rock, and hold the guide-plate, and consequently the drill, from both longitudinal and lateral displacement. A workman sits upon this guide-plate when it is in use, and with his hands holds and aids in direoting the drill in its Vertical descent. The pins c are made screw-pins for purposes of adjustment, the face of the rock not being always one general level.

The letter d denotes the round hole drilled in the rock before the device of this patent is used.

lt is obvious that the means and mode herein described of guiding atool for cutting V-shaped groovesin the wallof a previously-drilled round hole are applicable where but a single groove is cut at a time, and where, in the following claims, I mention wings a' a', I include the use of one or more such Cutting-wings.

Ooteniporaneously with the filing of this present application an application is filed by John L. L. Knox and myself for patent on means and method for. blasting out rock corners, Serial No. 208,727, and what is described and claimed in the said application of Mr. Knox and myself is not claimed as my invention herein.

I am made aware of the contents of Letters Patent to Henry Palmer for drill for artesian Wells, No. 54,199, dated April 24, 1866, and of the contents of Letters Patent to Charles Snedekum for forked drill, No. 337 ,351, dated March 2, 1886, and what is described and claimed in the said two Letters Patent last nientioned is not claimed as my invention herein.

I claim as niy improvenlentfl IOG 1. The square-bodied drill a, bearing the mol'tisein one edgethereof, and the screw-pns lateral Cutting-Wings a'c, in combination With c, all substantally as described, and for the the guide-plate b, having the square mortise pul'pose set fort'h.

1`u one edge thereof, all substantally as de- THOMAS MURDOCK. 5 scribed, and for the purpose set forbh. vitnesses:

2. The square-b'odied drill a, in combina- OHAS. A. JARVIS,

tion With the guide-plate b, having the square H. A. GORNWALL. 

